Demountable blade bit



May 711940 A. c. CATLAND 2.199.692

DEMOUNTABLE BLADE BIT Filed Aug. 11. 1937 EL El?.

2 She'ets-Sheet l IMay?, 1940. A, C, CNI-LAND 2,199,692

DEHOUNTABLE BLADE BIT Filed Aug. 11, 1937 sneeis-sheet 2 WW @y l .4/

CQWM

Planea M., 1, im

t UNITED Y sTATEs PATENT OFFICE Globe Oil Tools Comp any, Los Nietos, Calif..

a corporation of California Application August 11,1937, Serial No. 158,515

6 Claims.

This invention relates to well drilling tools and relates more particularly to a well bit for use in the rotary method of well drilling. A general object of this inventionis to provide a practical,

3 effective, well bit embodying demountable and replaceable -cutting blades.

It is highly desirable to make the blades of well drills demountable so that they may be replaced when worn or when it is desired to employ blades of diiferent character. However,

great diiiicuity hasv been encountered in providing a practical demountable blade well bit. In bits of this character heretofore introduced the blades hammered loose -inthe shank causing wearing of the shank and breaking of the blades.

Another object of this invention is to provide a .well bit embodying demountable blades secured to the bit body in such a manner that they cannot work loose or hammer against the body. i

g Another object of this invention is to provide a demountable blade bit of the character mentioned in which the heavy cutting thrusts or forces are transmitted directly between the bit body and the blades and do not cause loosening s of the blades or the securing means.

Another object of this invention is to provide a well bit of the character mentioned embodying novel means for locking the blades to the head or body of the tool.

so Another object of this invention is to provide a bit of the character mentioned in which the cutting parts are formed, positioned and related to act on the entire bottom wall of the well bore and to be particularly rapid and efficient in their cutting action.

tion will be fully understood from the following detailed description of a typical, preferred form and application of the invention, throughout 4l which description reference is made to the accompanying drawings, in which:

Fig. 1 is a front elevation of the improved bit provided by this invention. Fig. 2 is a side elevation of the bit. Fig. 3 is a bottom view of' the 6o bit. Fig. 4 is an enlarged fragmentary vertical detailed sectional'view taken as indicated by line 4 4 on Fig. 3. Figs. 5 and 6 are transverse detailed sectional views taken as indicated by lines 5-5 and 0 6, respectively. on Fig. 4. Fig. 7

u is a fragmentary vertical detailed sectional view (ci. ass-s1) showing one of the choke nipples and adjacent parts. Fig. 8 is a rear elevation of one of the blades. Fig. 9 is a horizontal sectional view taken as indicated bly line 9-9 on Fig. 8. Fig. 10 is a front elevation of one of the other blades. g Fig. 11 is a horizontal sectional view taken as indicated by line II-II on Fig. 10 and Fig. 12 is an enlarged fragmentary vertical detailed sectional view taken as indicated by line I2-I2 on Fig. 6. 10

The improved well bit provided by this invention includes, generally, a shank or body I0, a center cutter I I on the lower end of the body I0, pairs of demountable blades I2 and I3 and means I4 removably securing the pairs of blades I2 15 and I3tothe body I0. I

The body I0 is adapted to be connected with the lower end of a rotary well drilling string. In practice the body Ill is an lelongate member provided at its upper end with a threaded pin zo I5 for facilitating its connection with the drilling string. .The lower portion of the body I0 may be enlarged in diameter to carry the cutting parts. The enlarged lower portion of the body I0 may have two diametrically opposite at side g5 faces I6. Pockets or recesses I1 are provided in diametrically opposite sides of the large lower portion of the body I0. The recesses I1 are of substantial length and extend upwardly from the lower end of the body. 'Ihe two recesses Il are 30 o`set rearwardly relative to the direction of; rotation of the bit with respect to a diametric plane parallel with the side faces I6. .The upper Walls I8 of the recesses I1 are iiat and substantially horizontal. 'I'he bottom walls or inner walls of 35 the recesses I1 are at and substantially vertical. In accordance with the invention the recesses I1 have `fiat inwardly convergent side walls I9. The side walls I9 are inclined downwardly and forwardly relative to the direction of rotation of 40 the bit. Vertically or longitudinally extending grooves 20 are provided in thecorners of the recesses I1 where their side walls I9 join their inner walls. The grooves 20 are preferably partially cylindrical in cross section to facilitate the manufacture of the body I0. A horizontal iiat walled groove 2| is provided in the inner wall of each recess I'I. 'Ihe grooves 2I extend between and communicate with the spaced grooves 20.

The center cutter II is provided to cut away the earth formation at the center of the well bore. The center cutter II projects from thellower end of the body I Il andfis demountable and replaceable. The removable center cutter II includes a body or pin 22 which is threaded in a central socket 23 inv the lower end of the body I0. The cutter II further includes iish-tail blades 24 on the lower end oi' the pin 22. The blades 24 project downwardly beyond the lower end of the body I0. The blades 24 are preferably of substantial width to act on or remove the earth formation remaining within the path of the blades I2 and I3. The center cutter II may be readily removed from the body I0 by unthreading its pin 22 from the socket 23.

The blades I2 and I3 are the principal cutting elements of the bit. There are two pairs of blades I2 and I3, one pair being secured in each recess I1. The blades I2 are arranged in the forward portions of the recesses I1 relative to the direction of rotation of the bit while the blades I3 are arranged in the rear portions of the recesses. The blades I2 and I3 may be substantially identical although they embody lock parts of the means I4 that are slightly different in position. The blades I2 and I3 are platelike elements having ilat parallel opposite sides. Shanks 25 and 25a of reduced width are provided on the upper ends of the iblades I2 and I3, respectively. Suitably bevelled reaming edges 26 and 26a are provided on the blades I2 and I3. The reaming edges 2B and 216e are of substantial length and when the blades are in position on the body I0 the edges 26 and 2lia extend from above the lower end of the shank to points some distance below the lower end of the shank. The` lower ends of the blades I2 and I3 are shaped' to have effective cutting engagement with the earth formation. In the particular case illustrated in the drawings the lower ends of the blades I2 and I3 are alike, the blades I2 each having two stepped cutting edges 21 and 28 and the blades I3 each having two similar cutting edges 21 and 28a. It is to be understood that the lowenends of the trailing blades I3 may be different from the lower ends of the leading blades I2, for example, their lower ends may be straight and without the notch or step shown.v

The means I4 for securing the blades I2 and I3 to the body IU is an important feature of the invention and is such that the blades may be easily and quickly removed from the body I 0 for replacement, etc. The means I4 includes ribs or tongues 30 and 30a, respectively, on the inner vertical edges of the blades I2 and I3. The tongues 30 and 3l]a are provided to cooperate with the grooves 20, and are partially cylindrical in cross section to accurately t the grooves. The tongues 30 and 30a are preferably formed integral with the blades I2 and I3. Notches 3l are provided in the inner edges. of the blades I2 and extend through their tongues 30 and similar.

notches 32 are provided in the inner edges of the blades I3 and extend through their tongues 30a. When the blades I2 are in cutting position on the shank I0 their forward sides bear on the forward walls I9 of the recesses I1 and their upper ends bear directly on the upper walls I3 of the recesses. are in place their rear sides bear on the pitched rear side walls I9 of the recesses I1 and their upper ends bear directly against the upper walls I8 of the recesses I1. The tongues 30 and 30 cooperate with the grooves 20 to lock the blades I2 and I3 against outward or radial displacement and movement relative to the body I0. It will be observed that the blades I2 and I3 bearing against the inclined side walls I9 of the recesses I1 slope. downwardly and forwardly with respect to the direction of rotation of the bit.

In a like manner when the blades I3 The means I4 further includes a wedge or block 33 arranged in each recess I1 to retain the blades I2 and I3 in place.

The blocks 33. are shaped and proportioned to properly cooperate with the blades I2 and I3 and to deilnitelyprevent'movement and hammering of the blades. The blocks 33 have dat upper ends v34 bearing against the upper walls I8 'ofthe recesses I 1. The outer sides of the blocks 33 may be convex and substantially ilush with the adjacent surfaces of the body I8. The inner sides 35 of the blocks 33 are at and vertical. A horizontal lug 36 is provided on the inner side 35 of each block 33. The lugs 33 fit the grooves 2| in the body I0 and cooperate with the notches 3| and 32 in the blades I2 and I3, respectively. The lugs 36 cooperating with the notches 3I and 32 definitely locate the blades I2 and I3 on the body I0 and assist in preventing downward displacement of the blades. The ends of the lugs 33 are at and cooperate with the iiat bottom or inner walls of the notches 3| and 32.

The sides 31 of the blocks 33 are inwardly convergent and are inclined downwardly and forwardly relative to the direction of rotation of the bit to ilatly bear on the rear surfaces of the blades I2 and the front surfaces of the blades I3. The blocks 33 are proportioned so that their inner sides 35 have suitable clearance with the inner Walls of the recesses I1 when their sides 31 are in cooperation with the blades I2 and I3. The inner corners of the blocks 33 may be shaped to receive portions of the tongues 30 and 3i)a that protrude from their grooves 20.

The means I4 includes securing members for attaching the blocks 33 to the body I8 and to urge the blocks inwardly against the blades I2 and I3 so that the blocks securely hold the blades on the body. In' the preferred construction two vertically spaced studs 38 project outwardly from the inner wall of each recess I1. The studs 38 may be threaded in openings 38 in the body I 0 and then welded to the body. Horizontal openings 40 are provided in the blocks 33 and receive the projecting portions of the studs 38. Nuts 4I are threaded on the studs 38 and bear inward-V ly against the blocks 33. The nuts 4I are preferably received in the outer portions of the openings 40. Cotter keys 42 may lock the nuts 4I against unthreading. The nuts 4I bearing inwardly against the tapered wedge-like blocks 33 urge the blocks against the blades I2 and I3 so that they securely hold the blades in place against the inclined and inwardly convergent walls I9. The tapered blocks 33 also urge the blades I2 and I3 inwardly to hold their tongues 30 and 30a tight' in the grooves 20.

The invention provides eiective means for flushing the cutter II and the blades I2 and for maintaining a proper circulation in the well. A

central longitudinal iiuid passage 43 extends the fluid from wearing away the body I 0. The

nipples 45 discharge immediately in front of the leading blades I2 and are effective in preventing mud and cuttings from accumulating on the* g5 blades. A central port 46 of reduced diameter extends downwardly from the reduced lower end of the passage 43 to the socket 23 where it communicates with a passage l1 in the pin 22. Two downwardly and outwardly inclined ports 48 communicate with the lower end of the passage 41 and discharge from the lower end of the cutter II in front of its blades 24.

It is believed that the operation of the bit provided by this invention will be readily understood from the foregoing detailed description. In operation the body Ill is connected with the lower end of a well drilling string and the bit is rotated and fed downwardly in the well in the usual manner. The leading blades I2 are effective in cutting away the formation at the bottom of the well bore and the trailing blades I3 assist in cutting away the formation and operate to stabilize the bit. The pairs of blades I2 and I3 make an annular out in the earth formation leaving a central portion. This central -portion of the earth formation is cut away by the center cutter II. The roaming edges 26 and 26 of the blades I2 and I3, respectively, ream the side wall of the well bore and assist in stabilizing and guiding the bit to drill a straight bore. The circulation fluid discharged from the nipples 45 and from the ports 48 flushes the blades and the cutter II and maintains a desirable turbulence in the bottom of the well.

The wedge blocks 33 forced or urged inwardly by the nuts 4I hold the blades I2 and I3 in tight contact with the surfaces of the body I so that the blades cannot hammer against the body. The wedge-like blocks 33 bearing inwardly against the blades I2 and I3 urge the blades radially inward as well as laterally against the side walls I9 of the recesses I1 dependably preventing hammering and Working of the blades. The upper ends of the blade Shanks 25 and 25' bear directly against the upper walls I8 of the recesses I1 for the transmission of the heavy drilling pressures. This relieves the studs 38 and the lugs 36 of these heavy forces, although the studs and the lugs may assist in the transmision of some of the cutting forces. As the inner sides 35 of the blocks 33 have clearance with the inner walls of the recesses I1 the blocks may be forced into very tight holding engagement with the blades I2 and I3 by tightening down the nuts 4I. When it is desired to replace the blades I2 and I3 it is only necessary to unthread the nuts 4I and then remove the blocks 33 to free the blades for removal. New blades or replacement blades I2 and I3 may be quickly assembled on the body I0 to recondition the bit or to change the eiiective cutting vdiameter of the bit. Y

Having described only a typical preferred form and application of my invention I do not wish to be limited or restricted to the specific details herein set forth, but wish to reserve to myself any variations or modifications that may appear to those skilled in the art or fall within the scope of the following claims.

Having described my invention, I claim:

1. A well bit comprising'a body having a recess 'with inwardly converging side walls, there being grooves in the body at the inner edges of said side walls, cutting blades engaged against said side walls, tongues on the blades cooperating with said grooves, and a'removable block in the recess having inwardly converging sides bearing on the blades to retain the blades in position, the 'grooves having open sides facing outwardly whereby the blades may be moved laterally to disengage their tongues from the grooves when the block is removed.

2. A well bit comprising a body having a recess with inwardly converging side walls, there being grooves in the side walls, cutting blades engaged against the opposite side walls of the recess, tongues on the blades cooperating with said grooves, a block in the recess having inwardly converging sides bearing against the blades, and

screw means removably holding the block inwardly against the blades to retain the blades in position, the grooves having open sides facing outwardly whereby the blades may be moved laterally to disengage their tongues from the grooves when the block is removed.

3. A Well bit comprising a body having a recess with inwardly converging side walls andan upper wall, there being grooves in the body at the inner parts of said side Walls, cutting blades engaged against said side walls and bearing upwardly against said upper wall, tongues on the blades fitting said grooves, a block in the recess having inwardly converging sidesA engaging the blades, and means holding the block inwardly in the recess.

4. A well bit comprising a body having an external longitudinal recess provided with walls converging inwardly toward the vertical axis of the body, cutting blades arranged against the opposite convergent walls of the recess, the inner edges of the blades having notches, a block in the recess having inwardly convergent sides bearing on the blades to hold them against said convergent walls, a part on the block cooperating with said notches, and means holding the block in the recess.

5. A well bit comprising a body having a recess with side walls, there being grooves in the side walls, cutting blades arranged against the side walls, tongues on the blades cooperating with the grooves to prevent outward movement of the blades, a block in the recess 'engaging the blades, said tongues having notches, a part on the block cooperating with the notches to prevent vertical movement of the blades, and means urging the block against the blades.

6. A well bit comprising a body having recesses in its opposite sides, said recesses having side walls converging inwardly toward the vertical center of the body, a cutting blade arranged against each of said side walls and projecting downwardly from the body, a block in each recess, the blocks having inwardly convergent sides bearing on the blades, means removably holding the blocks in the recesses, cutting parts on the projecting low portions of the blades, and a center cutter removably secured to the body and u 

